This invention relates generally to a measuring spring unit adapted to be incorporated in force measuring apparatus, the unit being arranged so as to have a directional force imparted thereto and, more particularly, to such a measuring spring unit which is selectively adjustable so as to be operable to measure forces within various different ranges.
Measuring instruments adapted to measure directional forces imparted thereto at selected measuring points in various industrial processes are well known. Thus, a measuring force is generally transmitted from the object being measured to the measuring instrument in a manner such that the measuring force received by the measuring instrument is then converted to a pneumatic or electrical measurement indication.
In this connection, it is often required to measure forces of different orders of magnitude, i.e., forces falling within ranges which are widely disparate from each other. In order to accommodate this condition, conventional measuring instruments have been provided with the capability of adjusting the extent of the range of forces which can be measured. Such provisions usually take the form of elaborately balanced lever arrangements having at least one adjustable lever ratio. However, these arrangements which are incorporated in conventional measurement apparatus of this type have not been found to be entirely satisfactory in that such lever arrangements are generally relatively elaborate, complicated, and require frequent adjustment.